package filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/*登录问题*/
@WebFilter(value = {"/addStudent.jsp","/LookStudentServlet"})
public class LoginFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //1.将请求和响应对象 转化HTTP相关
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response= (HttpServletResponse) servletResponse;

        //2.获取会话领域对象数据
        Object username = request.getSession().getAttribute("username");

        //3.判断用户名
        if(username == null || "".equals(username)){
            //重定向
            response.sendRedirect(request.getContextPath()+"/login.jsp");
            return;
        }

        //4.放行
        filterChain.doFilter(request,response);
    }
}
